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Fast chargeable carbon anode material with inner channels

a carbon anode material, fast charge technology, applied in the direction of carbon preparation/purification, cell components, electrical equipment, etc., can solve the problems of limited lithiation rate capability, limited capacity, cost, safety, energy density, power density of current electrode materials, etc., to achieve excellent capacity, rate capability and cyclability.

Active Publication Date: 2021-11-09
NEC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present invention provides an anode material for a lithium ion battery that has excellent capacity, rate capability, and cyclability.

Problems solved by technology

The greatest challenges in adopting the technology for large-scale applications are the energy density, power density, cost, safety, and cycle life of current electrode materials.
However, the small interlayer spaces (0.335 nm), the lack of Li-ion intercalation sites on the natural graphite basal plane, and the long diffusion range among the graphite interlayers result in a limited lithiation rate capability of graphite anode materials.
However, soft carbon usually has a limited capacity (around 250 mAh / g) and higher average potential while charging and discharging, it is difficult to be used in Li-ion batteries with high energy density.
Hard carbon has a capacity around 400 mAh / g, but its low density, low coulombic efficiency, and high cost make it difficult to use in batteries for EVs and PHVs at a low enough cost.
Other high capacity anode materials such as silicon and tin alloys have even worse lithiation rate capabilities because of the low kinetics of lithium alloying and the accessibility of lithium ion through thick SEI.

Method used

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  • Fast chargeable carbon anode material with inner channels
  • Fast chargeable carbon anode material with inner channels
  • Fast chargeable carbon anode material with inner channels

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0052]The material of Comparative Example 1 was used as a raw material. The material was subjected to a first heating (thermal shock activation) by rising temperature to 650° C. with a temperature rising rate of 30° C. / min in an oven under dry air atmosphere and kept at 650° C. for 2 hours. Then the temperature was dropped to less than 50° C. by nature cooling. After that, the oven was vacuumed and filled with 100% N2 in 15 minutes. The oven was then heated up to 1000° C. from less than 50° C. with the rising rate of 1° C. / min and kept in 1000° C. for 4 h. After the second heating process, the oven was cooled to less than 50° C. and the material is used as Example 1. Cross section SEM image of the material of Example 1 is shown in FIG. 4. It can be learned that the interlayers of the spherical carbon particles are etched by air to form inner channel 3. However, there is not so many cracks inside of the carbon particles because the first heating was carried out at the lower temperatu...

example 2

[0053]Example 2 was performed in the same manner as in Example 1 except for changing the first heating temperature to 750° C. Cross section image of the material of Example 2 is shown in FIG. 5. This sample was activated at a higher temperature than Example 1, so the inner channels 3 were created more inside of the core part.

example 3

[0054]Example 3 was performed in the same manner as in Example 2 except for changing the holding time of the first heating to 4 hours. Cross section image of the material of Example 3 is shown in FIG. 6. This sample was obtained in the same temperature with Example 2 but longer holding time. It can be learned that the inner core parts were heavily etched by air to increase inner channels 3.

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Abstract

To provide an anode material for implementing a lithium-ion battery that is capable of high-speed charging and excellent in cycle characteristics, and has high capacity. The anode material includes a spherical particle of graphite or graphite-carbon composite provided with pores on the surface and inner channels in the core part of the particle, the inner channels being interconnected to the pores.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a National Stage of International Application No. PCT / JP2015 / 004579 filed Sep. 9, 2015.TECHNICAL FIELD[0002]The present invention relates to a carbon anode material with inner channels in the core part interconnected to the surface pores of a graphite or graphite-carbon composite particle. The carbon anode material is useful for a fast chargeable anode material of a lithium-ion battery.BACKGROUND ART[0003]Lithium-ion (Li-ion) batteries have been widely used for portable electronics, and they are being intensively pursued for hybrid vehicles (HVs), plug-in hybrid vehicles (PHVs), electric vehicles (EVs), and stationary power source applications for smarter energy management systems. The greatest challenges in adopting the technology for large-scale applications are the energy density, power density, cost, safety, and cycle life of current electrode materials. Of all the properties, the charging time as well as the power...

Claims

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Application Information

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Patent Type & Authority Patents(United States)
IPC IPC(8): H01M4/587H01M4/36H01M4/62H01M10/0525C01B32/05
CPCH01M4/587C01B32/05H01M4/366H01M4/625H01M10/0525C01P2006/11C01P2006/14C01P2006/16Y02E60/10
Inventor CHENG, QIANTAMURA, NORIYUKI
Owner NEC CORP